Description Historical activity that resulted
in contamination.

The Boone Dry Cleaners site is 0.2 acre former drycleaning site (currently a welding supply store) located in a mixed use area (industrial, residential, commercial) near downtown Jackson, TN. The establishment operated for 20 years between 1945 and 1977, the exact dates of operation are not known. Asphalt predominantly covers the site, with small strips of exposed soil present in the alley east of the site and on the north side. Standard drycleaning activities are suspected to be the source of chlorinated solvent (PCE, TCE, cis-DCE) constituents detected in soil and groundwater in the vicinity of the site. The Savings Oil Company which neighbors the site, is suspected to be the source of BTEX constituents detected in groundwater.

ContaminantsContaminants present and the highest amount
detected in both soil and groundwater.

Pathways and DNAPL Presence

Remediation Scenario

Technologies

Why the technology was selected:Bioremediation was thought to be the safest and most effective short- & long-term remedy for both soil and groundwater.

Date implemented:April 2002 (pilot test for enhanced bioremediation)

Final remediation design:The remedial design consisted of twelve 4" injection wells and eight 2" pilot test monitoring wells installed to a depth of 18-ft. One injection well was placed in the source area with five others placed parallel to the plume width, just upgradient of the source area end, at a 10-ft spacing. The remaining six wells were placed throughout the plume length, near or offset from the plume centerline. These wells were spaced between 20-30 ft apart. The eight pilot test monitoring wells were placed along the length of the plume downgradient of the upgradient injection wells and cross-gradient to the plume length injection wells. A baseline sampling event was conducted in April 2002 to establish pre-injection conditions. In May 1002, the wells were injected with a solution of corn syrup, simple green, and vegetable oil. This was continued on a two-week schedule until August with a one-time injection of emulsified soybean oil taking place in December. Effectiveness sampling was conducted in August 2002 and March 2003.
Excavation of soil within the source area occurred in December 2004. Approximate area of excavation, 22ftx22ftx12ft. Sodium lactate (Wilclear) was added to the
excavation.

Other technologies used:Excavation of soil within the source area occurred in December 2004. Approximate area of excavation, 22ftx22ftx12ft.

Results to date:The wells with the greatest PCE impact (PCE baseline concentration greater than 4-orders of magnitude higher than the PCE MCL) indicated a 85-95% decrease by August 2002. The March 2003 data indicated that one of these wells, which is located within the source area, maintained a concentration similar to the August 2002 level. The other well, located slightly downgradient of the source area, indicated a rebound to baseline concentrations. Another well, located slightly outside the centerline between these wells, indicated a rebound to greater than baseline concentrations. The baseline concentration for this well was about 2-orders of magnitude higher than the MCL. Wells located about midway along the plume and up to the leading edge, indicated no PCE detections. Baseline concentrations for these wells ranged from MCL levels up to about 2-orders of magnitude.

Next Steps:Activities planned at the site include nutrient injections over the next two years with periodic effectiveness monitoring. In addition, sampling is planned in the future to assess the remedy effectiveness.

Costs

Cost
for Assessment:

Cost breakdown unavailable at this time.

Cost
for Operation and Maintenance:

Total
Costs for Cleanup:

Lessons Learned

1. Remedial designs that call for injections of nutrients using oil containing nutrient enriched emulsions should consider the separation of oil from the emulsion. The remedy for this site added nutrients via a soybean oil, maple syrup, and simple green emulsion and vegetable oil is now floating on top of water.